1. Field of the Invention
The present invention relates to computer control systems and, more particularly, to a computer control system for an oil refining unit.
2. Description Of The Prior Art
Heretofore, in controlling solvent refining units using control systems as described and disclosed in U.S. Pat. Nos. 3,666,931 (issued May 30, 1972), 3,686,488 (issued Aug. 22, 1972) and 3,718,809 (issued Feb. 27, 1973), all of which issued to R. A. Woodle, inventor of the present invention, and assigned to Texaco Inc., assignee of the present ivention, concern themselves with either obtaining optimum yields of refined oil and extract oil or obtaining a maximum yield. In those patents the solvent flow rate was considered a fixed parameter. The present invention differs from those patents by controlling the solvent flow rate as a variable and achieving control of parameters not previously controlled directly.